PMID- 7594883
OWN - NLM
STAT- MEDLINE
DCOM- 19951129
LR  - 20110729
IS  - 0300-9165 (Print)
IS  - 0300-9165 (Linking)
VI  - 47
IP  - 8
DP  - 1995 Aug
TI  - [Expression of oncogenes, growth factors and their receptors in follicular 
      growth, regression and atresia: their roles in granulosa cell proliferation and 
      differentiation].
PG  - 738-50
AB  - Ovarian folliculogenesis is a dynamic and complex process during which follicles 
      undergo tremendous growth and maturation. Beginning as a single layer of 
      pregranulosa cells surrounding the immature oocyte, granulosa cells actively 
      proliferate and differentiate until the time of ovulation. The proliferation of 
      granulosa cells is necessary not only for follicular growth but also for creation 
      of the unique micro-environment for oocyte maturation. Although the primary role 
      of follicle-stimulating hormone (FSH) in granulosa cell growth and function is 
      well established, detailed mechanisms regulating folliculogenesis are not 
      understood. Thus, in this study the role of several growth factors, such as 
      thyroid hormone, insulin, insulin-like growth factor-I (IGF-I), epidermal growth 
      factor (EGF), transforming growth factor-beta (TGF beta) and tumor necrosis 
      factor-alpha (TNF alpha) were evaluated for their potential as endocrine, 
      paracrine and/or autocrine regulators of granulosa cell proliferation and 
      differentiation. Furthermore, the granulosa cell is one of the most rapidly 
      growing normal cell types known, so a possible participation of the myc oncogene 
      in granulosa cell proliferation was assumed. Actually, we have found that myc 
      oncoprotein is expressed in granulosa cells in a stage-limited manner during 
      follicular growth and regression. Abundant expression of myc oncoprotein in 
      granulosa cells was apparent only at the preantral follicle stage. Moreover, 
      c-myc mRNA was expressed abundantly only in the granulosa cells of the 
      less-mature, small follicles. The stage-specific expression of c-myc oncogene in 
      immature granulosa cells early in follicular growth may suggest the intriguing 
      possibility of c-myc oncogene participation in the autonomous growth of the 
      immature follicles during the early stage of folliculogenesis. We have also shown 
      that erb-A oncogene, which encodes a thyroid hormone receptor, was expressed more 
      abundantly in small-follicle granulosa cells than in large-follicle granulosa 
      cells. Thus, it is possible that the expression of these oncogenes, either alone 
      or in combination, may play a role in autonomous granulosa cell proliferation 
      early in follicular development. On the other hand, thyroid hormone, insulin, 
      IGF-I and EGF were found to be act as biological amplifiers (up-regulators) of 
      FSH actions in granulosa cells, whereas TGF beta and TNF alpha were shown to act 
      as down-regulators of FSH actions in granulosa cells. Greater than 99% of ovarian 
      follicles undergo atresia during reproductive life. It has been shown that 
      apoptotic cell death is the molecular mechanism underlying follicle 
      atresia.(ABSTRACT TRUNCATED AT 400 WORDS)
FAU - Maruo, T
AU  - Maruo T
AD  - Department of Obstetrics and Gynecology, Kobe University School of Medicine.
LA  - jpn
PT  - English Abstract
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Japan
TA  - Nihon Sanka Fujinka Gakkai Zasshi
JT  - Nihon Sanka Fujinka Gakkai zasshi
JID - 7505749
RN  - 0 (Growth Substances)
RN  - 0 (Receptors, Growth Factor)
SB  - IM
MH  - Animals
MH  - Cell Differentiation
MH  - Cell Division
MH  - Female
MH  - *Follicular Atresia
MH  - Follicular Phase/*physiology
MH  - *Gene Expression Regulation, Neoplastic
MH  - Granulosa Cells/*cytology
MH  - Growth Substances/*physiology
MH  - Humans
MH  - *Oncogenes
MH  - Ovarian Follicle/*physiology
MH  - Receptors, Growth Factor/*physiology
EDAT- 1995/08/01 00:00
MHDA- 1995/08/01 00:01
CRDT- 1995/08/01 00:00
PHST- 1995/08/01 00:00 [pubmed]
PHST- 1995/08/01 00:01 [medline]
PHST- 1995/08/01 00:00 [entrez]
PST - ppublish
SO  - Nihon Sanka Fujinka Gakkai Zasshi. 1995 Aug;47(8):738-50.